All About Myopia (Nearsightedness)
Myopia, also known as nearsightedness, is when the eyes see close-up objects clearly, but objects far away are blurry. It occurs when the eyeball is too long and/or the cornea is too curved. Because of this, light rays focus in front of the retina instead of directly on the surface. For example, reading a book is no trouble, but reading distant road signs while driving is difficult for someone with nearsightedness.
- Eye strain
- Fatigue or headaches from doing distant tasks
Nearsightedness is mostly inherited, similar to the other refractive errors, and typically begins in childhood.
Who Gets Myopia?
Myopia usually begins during childhood and stabilizes in early adulthood. However, in some cases, nearsightedness can worsen with age. That is why early eye exams for children and annual eye exams are so important to detect both early and ongoing signs of myopia and other eye conditions.
Types of Myopia
The following conditions are rare and more severe forms of myopia:
- High Myopia: This form of myopia is where the eyeball grows to be very long from front to back. Those with high myopia have a diopter (D), the unit used to measure the correction power of the lens, of -5.00 to -6.00 D or higher. Although it doesn’t generally lead to vision loss in itself, it does increase your chances of developing other conditions such as a detached retina, cataracts, and glaucoma.
- Degenerative Myopia: This is a rare type of myopia, also called pathological or malignant myopia, that is usually hereditary. The lengthening of the eyeball occurs very quickly and becomes extremely elongated with no way to treat it. Typically by the teenage or early adult years, it will develop into severe myopia. Degenerative myopia can lead to having a detached retina, abnormal blood vessel growth in the eye, and glaucoma.
How to Correct Myopia
Prescription eyeglasses, contacts, or refractive surgery can be used to correct myopia. People with myopia have a glasses or contact lens prescription with a negative (-) number. The higher that number is, the stronger the prescription. For example, -3.50 is stronger than -2.00. Aspheric high-index lenses are a great option for those with nearsightedness because they are light and thin, even with strong prescriptions.